Demon's Poison
by Higuchimon
Summary: [au: angel/demon: Angels, Demons, & Deciding Factors 2] In escaping from Yuuri, Shun found himself injured by demon poison. Demon poison can do horrible things, even to an angel. Perhaps especially to an angel.
1. Chapter 1

**Disclaimer:** I own nothing involved in this story unless I invented it myself. This is written for fun, not for profit. All forms of feedback eagerly accepted. Concrit is loved the most, but everything is welcome.  
 **Author:** Higuchimon  
 **Fandom:** Yu-Gi-Oh Arc-V  
 **Series:** Angels, Demons,  & Deciding Factors|| **Story Title:** Demon's Poison  
 **Characters:** Shun, Yuuto, Ruri|| **Pairing:** N/A  
 **Word Count:** chapter: 2,327|| **story:** 2,327|| **Chapters:** 1/4  
 **Genre:** Friendship, Angst|| **Rated:** PG  
 **Challenge:** Diversity Writing Challenge, H8, multi-chap with exactly 4 chapters; Easter Egg Basket Advent 2016, day #8, mention at least 5 separate colors; Valentine's Day to White Day 2016 day #4, redo a challenge prompt (Dice Gods, Shun  & Yuuto friendship); Advent 2015, day #3, write about a friendship; Catch the Yuus & Bracelet Girls: Yuuto; Word Count Set Boot Camp, #41, 8,373 words  
 **Notes:** This takes place in the same world as **Angel's Rest** , and takes place after it. For reference, Ruri, Shun, and Yuuto are all angels, whilst Yuuri & Dennis are demons.  
 **Summary:** In escaping from Yuuri, Shun found himself injured by demon poison. Demon poison can do horrible things, even to an angel. Perhaps especially to an angel.

* * *

Shun drew in a few sharp breaths and peeled the leather back from his injured leg. He would've used some of the same language he had when he'd fought the demon Yuuri, but his sister hovered not that far away, and he tried to curb his language around her.

Frankly, he knew that she knew the same sort of profanity that he did, but that didn't stop him from at least trying to keep some of those words out of her ears.

Yuuto knelt in front of him, fingers gently prodding at the streaks of blood and the marks from the thorned whip. Shun couldn't stop himself; the words came out of him regardless. Ruri rested a hand on his shoulder.

"Go ahead, you shouldn't hold it in."

He grunted at that, fingers digging into the moss-covered rock he sat on. Haya lay in his lap, purring softly, kneading against his leg. He'd never been so glad that his little cat came with him as he was today. He still thought he could've gotten away from Yuuri or even beaten him if he'd needed to, but Haya made it easier.

"How bad is it?" he asked, directing his attention back to Yuuto, who kept on probing the wounds.

"I've seen worse, but he used some kind of demon poison." Yuuto frowned down at Shun's muscled leg. "I'm not sure of how to treat it."

That wasn't surprising; they all knew how to deal with most kinds of injuries engaged in battle against demons, but poison was something else altogether.

"We're going to have to go to the city, aren't we?" Shun made a face at that. The glistening crystal-white city of Heartland, home of the angels, would probably have someone who knew how to deal with demonic poison. Shun just didn't like going there very often, especially not when something like this happened.

Yuuto carefully rinsed his scarf in the nearby river and washed away the dried blood from the wounds. If Shun looked close enough, he could see a tinge of green around where the thorns dug into him, and his leg throbbed, streaks of pain arching up it more and more. He didn't think he could put it down on the ground if he needed to.

Thankfully he wouldn't need to. Being able to fly was going to come in very handy. But it would get worse. He could _feel_ it getting worse.

Yuuto also hadn't answered Shun's question, but he didn't have to. There wasn't anywhere else around that could help, and he wasn't sure if that would either.

"Come on. The sooner we get back, the better," Yuuto said, reaching out one arm to help Shun to his feet. Ruri helped on the other side, and he did not miss how pale she was. He didn't want her to blame herself for what happened. He'd gone there on his own, when he could've at least asked Yuuto to come along, and what happened after that was the fault of the demon, no one else's.

He scooped Haya up, and the cat obligingly nestled into the hollow of his neck, claws digging into Shun's leather shirt there. It was a position Shun taught him once he'd resigned himself to Haya staying with him and wanting to fly whenever possible.

Yuuto and Ruri watched as Shun beat his wings faster and faster; he couldn't do his normal running takeoff with his leg throbbing the way it did, but he'd figured out standing takeoffs years ago. They weren't his best, but they could get him into the air, and on his way.

"Big brother..." Ruri murmured; it didn't usually take him this long to get up. But he waved her concerns away, until he could feel the wind catching at his wings, and sprang into the air.

He hated acknowledging how clumsy his 'spring' actually was and paid attention to the fact one dark blue feather spiraled downward once he was finally in the air. He wanted to pick it up, but he couldn't get a good angle on it, and he didn't want to mention it to Ruri or Yuuto.

 _I don't like the look that Yuuri had. And he already has my sword._

For that alone, Shun knew he'd come back to the demon lands and look for what was his, and that would risk encountering Yuuri again. He hadn't enjoyed it the first time and he doubted he would a second But he couldn't let it go.

Neither of them offered him a hand, though he could tell they wanted to. He would've refused it if they had. He could still move on his own. He didn't need that much help. It was enough that they'd come here after him in the first place.

They paced him through the air, Ruri swooping around in large circles to keep an eye out for any trouble, Yuuto staying close in case he had any more problems.

"She wanted to come after you as soon as we found out where you were going," Yuuto murmured as they flew along. "She kept saying how you were doing this to keep her safe."

Shun rolled his eyes. "She wanted to come out this way herself. At least now we know that it's _not_ safe." And if he'd bough that knowledge with pain, then at least it turned out to be useful knowledge.

Yuuto just gave him a mildly amused look that Shun mostly ignored. He had other things on his mind.

"That was Yuuri, wasn't it?" Yuuto said after another few wing-flaps. "I recognized him."

Shun couldn't help a quick snort. "I'd be surprised if you didn't. Wasn't having three of you enough?" One Yuuto, one Yuugo, and one Yuuya. And a Yuuri.

Granted, they'd known of Yuuri for a century or so, but without him popping up to shove his lookalike face in their problems, Shun managed to avoid thinking about him. He wasn't sure of how much longer he could go on doing that.

"I would've thought so," Yuuto replied, a hint of amusement flickering in his gray eyes. "We'll have to do something about him." His gaze fell on the empty sword sheath between Shun's wings. "Your sword?"

Shun just shook his head. He didn't want Yuuto to start trying to get it back for him. He'd made his own mistakes and he'd clean up his own messes.

From the way Yuuto looked at him, Shun had a very strong suspicion that he knew or guessed what Shun's own plans were. They weren't hard to figure out, not with someone who knew him as well as Yuuto did anyway. He would have to make sure something or someone kept Yuuto occupied once he was ready to go in search of his weapon. Maybe he'd ask Yuuya to lend a hand. If anyone would be able to distract Yuuto when he knew Shun had plans that would likely end up with him in even more pain, it was Yuuya.

The problem with that was that Yuuya would want to know why he had a need for Yuuto out of his way for a while. He'd work that out later.

Getting to the city took longer than Shun wanted it to. By the time they landed – or in his case nearly fell – on the balcony of the closest healer, all Shun wanted to do was curl up and sleep and hope the pain wasn't there when he woke up. He didn't need to move his feet very much to fly, but the little bits he did were harder than ever to do. The pain clawed its way up his leg and had nearly reached his waist, a shimmering scarlet claw that dug deeper and deeper into him with each moment.

Stars sparkled overhead in the night-blue sky, blocked out for a few seconds as the healer tossed back their curtain and stepped outside.

"What's the – oh, I see." They turned a firm look onto Shun's leg. "Poison, hm?"

"Yes. I ran up against a demon." He didn't really want to say anything else about it. He twisted around as best that he could, spreading his wings to get himself into a better position, wincing at the way the moving hurt far, far more than it should have.

"Demon poison's nasty," the healer muttered, bringing out a bag of remedies and starting to do their own check over Shun's leg. "Comes in a lot of different flavors. Didn't say anything to tell you what this one could do, I guess?"

Shun had to take a moment to think about what the healer meant. The longer the pain lanced through him, the harder it became to actually think that well. He shook his head, thoughts slowly sludging around in his head. "No." For once he wished he knew a little more about Yuuri, enough to guess at what kind of poison he'd be likely to use. It didn't feel like he was _dying_ , and something that could kill an angel would've probably already done so anyway.

"Of course not." The healer shook their head, hands moving over Shun's leg, probing more deeply than Yuuto had. Shun hissed, and found a hand in his, one that he gripped without thought, and heard Yuuto hissing as well.

"Don't worry about it," Yuuto told him when Shun looked at him. "Just do your best."

Shun had no arguments for that. He couldn't entirely put himself together enough to find one either. The more the healer worked, the more the pain _hurt_ , and the tighter he gripped onto Yuuto's hand.

Ruri stayed on his other side, and her slim hand found its way around his as well. He gripped both of them harder and harder, wishing that he had that foul creature's neck between his hands instead of theirs. He could squeeze then, squeeze until the neck snapped, and if that didn't kill Yuuri, then he'd find something else that would do it, and it would feel _so good_.

"There," the healer said after a timeless stretch where all Shun could think of was pain and joy at the thought of killing Yuuri. "I've cleaned out all of the wounds and applied one of the more general remedies against demonic poison. This one isn't one I've come across before. I'll need a larger sample before I can work out the antidote to it."

Shun dragged his eyes open, meeting the healer's sea-green ones. "What do you mean?" He knew that it should make sense, but it didn't. Not much did seem to make sense right now, except for pain and the desire to unleash heartfelt revenge on the one who'd caused it. That mess of purple and pink hair, those hideous eyes, the ridiculous outfit – who needed two capes or coats or whatever anyway – all of it floated in the back of his mind, a mocking laugh and that hideous, evil, twisted smile shining bright in his memories.

The only way he could get rid of it would be to get rid of Yuuri. He didn't know how he knew, but it made sense. Yuuri did this to him and he would know how to fix it.

Shun started to stumble to his feet, hissing out even fouler language than he'd used before when another purple-pink bolt of pain shot through him. Ruri and Yuuto stood beside him a heartbeat later, each gripping onto one shoulder.

"You're not going anywhere," Yuuto told him. "Don't make me put you down."

It wouldn't have been the first time he did, and Shun doubted it would be the last. Despite the disparity in their sizes, Yuuto held a far stronger punch than he did, and Shun knew if Yuuto got a good hit in, then he'd be unable to do anything but lay in his bed for hours. Hours that Yuuto would likely use to get hold of Yuuri himself.

That wouldn't happen. He'd gotten into this on his own and he'd get it out on his own _no matter what_.

"I have to get more of that poison," Shun growled instead. "I have to."

Ruri patted him on one shoulder as they helped him inside the healer's tower chambers, where patients who couldn't return to their own homes rested. "We know we need more of it. Don't you worry about it. We'll take are of it." Her eyes flickered with rage almost as strong as his. "And if we can bring that demon's head back, we'll do that too."

Yuuto sighed at both of them. "We can worry about revenge later. We need to make sure Shun's all right first."

Shun paid little enough attention to what they were saying. He needed to get back in the air, but they wouldn't let him, not yet. As much as it hurt to think right now, a silver sliver of cold planning slid through him.

He would rest. He would let them think he was sound asleep. Then while they were off trying to find the demon, he would leave. He would be able to locate him much quicker, and he would return with not only the demon's poison but that evil whip, too. Yuuri wouldn't be able to do to anyone else what he'd done to Shun.

The lights faded around him as he found himself tucked up in a warm bed, wings folded close around him. The rest he'd gotten while under the influence of the Angel's Rest flowers seemed far away now. A small spot of warmth rested at the top of his neck, above his wings. Haya. He would have to leave Haya here. It wouldn't be safe otherwise; he knew that now. Yuuto and Ruri could take care of him while Shun was away. He wouldn't be away that long.

Shun didn't know when his half-formed visions of strangling Yuuri and the pain ceasing slid into dreams of doing much the same.

 **To Be Continued**

 **Note:** Thank you for reading and I hope that you enjoyed the chapter. Please let me know what you thought of it if at all possible.


	2. Chapter 2

**Disclaimer:** I own nothing involved in this story unless I invented it myself. This is written for fun, not for profit. All forms of feedback eagerly accepted. Concrit is loved the most, but everything is welcome.  
 **Author:** Higuchimon  
 **Fandom:** Yu-Gi-Oh Arc-V  
 **Series:** Angels, Demons,  & Deciding Factors|| **Story Title:** Demon's Poison  
 **Characters:** Shun, Yuuto, Ruri, Yuuri|| **Pairing:** N/A  
 **Word Count:** chapter: 2,111|| **story:** 4,438|| **Chapters:** 2/4  
 **Genre:** Friendship, Angst|| **Rated:** PG  
 **Challenge:** Diversity Writing Challenge, H8, multi-chap with exactly 4 chapters; Easter Egg Basket Advent 2016, day #8, mention at least 5 separate colors; Valentine's Day to White Day 2016 day #4, redo a challenge prompt (Dice Gods, Shun  & Yuuto friendship); Advent 2015, day #3, write about a friendship; Catch the Yuus & Bracelet Girls: Yuuto; Word Count Set Boot Camp, #31, 9,359 words  
 **Notes:** This takes place in the same world as **Angel's Rest** , and takes place after it. For reference, Ruri, Shun, and Yuuto are all angels, whilst Yuuri & Dennis are demons.  
 **Summary:** In escaping from Yuuri, Shun found himself injured by demon poison. Demon poison can do horrible things, even to an angel. Perhaps especially to an angel.

* * *

"He's not asleep?" Ruri murmured, trying to keep her voice down to where he couldn't hear her in case she was right. Yuuto shook his head.

"He is. He's just talking in it, that's all." He couldn't keep the worry out of his voice. None of them had ever encountered demonic poison like this before and what effect it could have on an angel worried all three of them, him, Ruri, and the healer.

But the only way they could deal with this was to go and get that sample, and the sooner the better.

He let the curtain drop and turned toward the balcony, Ruri only a few steps behind her, worry still bright in her eyes. The healer already had promised to watch over Shun until they returned. Neither of them savored returning to demon lands, especially not so soon and under cover of night, but waiting until dawn wasn't an option, not with Shun already as strange as he'd become.

Silently they took to the air, following their own trail back. Yuuto didn't mention it to Ruri, but he wanted to make certain they retrieved Shun's sword as well while they were there.

 _He's not going to have any excuses to go back there._

He, Yuuya, and Yuugo had no idea of why they all looked like one another, with only mildly different points such as hair and eyes, let alone why a demon shared those features. But while Yuuto could and did get along reasonably well with his other two lookalikes, all three of them loathed Yuuri, just from the little interaction they'd had during the combat a century or so ago.

Apparently it was mutual. He'd never considered it might not be, but given the way that he'd glared at them when they'd come for Shun, that was definite proof.

They'd give Yuuri cause to do more than just glare, though, once they finished tonight's work. But whatever he thought would be 'revenge', they wouldn't allow it.

Every angel knew _something_ about magic of some kind. Shun's tended more towards those that could support him in combat, with a taste of a bond to animals – the way Haya cuddled him gave pure evidence of that. He also had a connection to raptors of all kinds, falcons especially.

Yuuto's involved going unseen, as if he were little more than a shadow. He could extend it to others, and did so for Ruri, just as he had when they'd gone for Shun before. It worked on demons, it seemed, since Yuuri hadn't noticed them until they'd revealed themselves.

 _If I have to call the others to keep Yuuri away from Shun after this, I will._

His magic was that of phantoms, shadows, and ghosts, and for reasons that no one could yet fathom, it grew stronger whenever it worked in tandem with Yuugo and Yuuya. It was the same for them; each of theirs grew stronger when the other two were around.

 _Would Yuuri's affect ours too? Make it weaker, since he's a demon? Or would his get stronger because of us?_

That wasn't the most settling thought and he pushed it aside in favor of keeping an eye on Ruri. She looked as silent and angry as Shun ever had, and if they weren't so close to the demon lands, he would've asked what was on her mind. Though he thought he already knew: the same thing on his, Shun and the demon Yuuri and how much they'd have to hurt Yuuri to get the poison away from him. It wasn't a fight he favored, but it was one he believed they'd have to win.

They passed over where Shun had been when they'd found him, and Yuuto gave a quick look to ascertain the demon wasn't there. No sign at all of anyone there, nor Shun's dropped sword. Yuuto hadn't expected that, in truth, though it had been a small, fleeting hope.

The demon lairs rose up not that far from the clearing, at least not far by angel wings. No lights lit it, for demons didn't need light to see by. Yuuto back-winged and hovered in place for a moment before he found a rocky outcropping to perch on and gestured Ruri to join him.

"How do we find him?" she asked as she did so, and he nodded.

"Just what I was wondering." Yuuto stared at the lairs, only visible against the night sky from where they stood. _We should've thought this out more._

"Well, hello, there!" It was a cheerful voice, far too much for any demon, but one that they both recognized. Ruri and Yuuto both leaped up, weapons close at hand, as an arcane flame rose up between one gloved hand and one that wasn't.

Dennis's smile hadn't changed in the years since they'd last seen him. He pouted a little as he looked from one of them to the other.

"Honestly, is that any way to say hello to someone who could help you?"

Ruri's grip on her swords didn't slacken at all. "Why would you help us?"

"I have my reasons." Dennis shrugged, running one finger through the flame that burned between his hands. "But I suppose you're going to want them before you believe me, aren't you?"

Yuuto didn't move a muscle. "I can't say that I would believe you then."

"What do you even know about why we're here?" Ruri wanted to know. Yuuto nodded slightly; this bore a whiff of a trap and if it weren't for their need, they would both be gone from here.

Dennis smiled, the tip of his tail just barely visible twitching in the starlight. "You think Yuuri didn't tell me about your encounter earlier? You'll need something special to cleanse that poison from your friend. You're after a sample, aren't you?" He leaned forward, large eyes full of a demon's mischief. "I can get you one. For a price."

"A price." Ruri and Yuuto echoed the words a heartbeat after one another. Ruri inched forward. "What kind of a price are you after?"

Dennis hmmed, eyes flicking between the two of them for a moment or two. "It's nothing very much. Though I'm sure _you_ won't think so."

"Spit it out." Ruri was not in the mood to waste time. Every moment they stood here was one more that Shun writhed because of that demon poison.

"I want to meet Yuuya," Dennis said at last. "We have some interests in common and I'd like to speak with him about them." He raised one hand before either of them could bring up an objection. "I swear that I won't touch him or do anything other than speak to him. No magic, nothing at all."

Yuuto and Ruri exchanged a quick, meaningful look before returning their attention to Dennis. This wasn't something either of them wanted to do without thought: the thought they didn't have time to take.

"We'll talk to Yuuya about it," Yuuto said at last. "He'll decide if he wants to meet you. That's all we can do." What worried Yuuto was that Yuuya probably _would_ want to meet a demon. He'd talked about it before, wondering how they could be 'all that bad'.

Dennis smiled, a quick flash that made Yuuto wonder if they'd done the right thing or not. "Come with me, then. I'll take you to Yuuri's garden. It's where he has samples of that poison. And we'd better hurry."

"Why?" Ruri asked, unfolding her wings. Dennis shrugged.

"Because I don't know when he's going to come back and he'll be so annoyed if you're there."

"Where is he?" Yuuto wanted to know, also rising up to follow the other two.

"Off checking on something. I don't think you really want to know other than that."

All they could see Dennis by was the flame he still carried. Yuuto decided getting in and out would work best for everyone.

* * *

Yuuri moved with all caution through the lands of the angels. So far as he could tell, the angels didn't move around much at night, which was all to the good for him. The only current exceptions were already on their way out of there.

 _I suppose I should feel lucky we didn't cross paths._ He'd started on his way here some time after they'd departed where they'd tussled over Kurosaki Shun. They hadn't been able to make the kind of time that he did because of the injuries he'd dealt to the angel, but he'd also had to discuss certain matters with Dennis.

Anything that would delay his enemies would work in his favor tonight. But he wanted to see the results of his poison up close and personal.

 _Is he just in pain? Or could it be more? Worse?_ He hadn't considered it until after they'd left, but he'd never tainted an angel with his poison before. There wasn't any way that he'd pass up the chance to see it for himself.

Finding his way through the angel homes – too pretty, too clean, too pure for his taste by far – took longer than he liked and he had no idea of how to tell which one of these places harbored his prey.

Thankfully, Kurosaki Shun himself helped guide him.

"Shun!" It wasn't a familiar voice, but a familiar shape that burst out of one of the buildings and tried to reach for the skies. "Calm down! You need to rest!"

Yuuri hid behind a graceful column to watch what happened. That was indeed Shun, wings beating frantically, fingers clawing for the skies, one leg bare and bandaged, kicking frantically, but not getting very far.

 _Beautiful. Just beautiful._ Yuuri sighed in wonder. His poison did such lovely work already.

Shun's wings beat faster, a few stray feathers slipping out, a gust of wind knocking some toward Yuuri. He caught one between his fingers and took a look at it from a spark of curiosity.

 _What in the..._

He'd seen Kurosaki's wings before: much the same color as the angel's hair. Dark blue, edging to black, but _not_ black.

Not like the feather he held now, which wasn't just black, but gave off a faintly different aura than that of an angel. It wasn't quite demonic… not yet. It hung between the two types.

 _I wonder… could it be..._ Yuuri began to smile. He'd wanted to keep Kurosaki in torment for as long as possible. Perhaps he could do even better. He could torment _multiple_ angels with the use of _one_.

Or perhaps technically not an angel anymore, but the principle remained the same.

Whoever it was trying to get Kurosaki back under control managed to lure him down and back inside. But Yuuri knew where they were now, and he'd come armed with more than one way to keep his enemies at bay.

He didn't dare take too much time. Dennis could delay the other two only by so much. Quick as a flash he leaned forward, landing on the balcony's rail, and stepped inside, whispering spells to dismantle the wards he sensed. They'd been crafted to keep out demons, but with what was going on with Kurosaki, perhaps they weren't as strong as they could've been. He could think of no other reason why they didn't go off at his mere presence.

Kurosaki's companion slumped in a chair, wings drooping down wearily. Yuuri ignored them, moving to where he could see his target, twitching heavily in a cornered off area. He took each step with the greatest of care, wary of either of them awakening before he wanted them to.

He reached out to brush his fingers over Kurosaki's wings, wanting to know if the living feathers would give him the same feeling as the one he'd touched before. He shivered at the sensation; not only did they but it was even stronger. Not quite at his own level or that of any born demon, but there all the same. Corruption moving through Kurosaki, strengthening with every moment.

 _This is going to be_ _ **fun**_ _._ He held back a laugh, then froze when Kurosaki's eyes opened, still bright gold, but with a harsher glare to them now.

A glare that somewhat softened when he spied Yuuri, a hint of confusion and curiosity in his tone as he spoke a single word.

"Yuu-to?"

Yuuri blinked, then smiled as the most perfect of plans burst into his mind. It might not last for long, but it would be enough to accomplish the desire he wanted.

"It's me, K… Shun." He moved closer, one hand going down to touch the weakened angel's hand. "I've come to take you home."

 **To Be Continued**

 **Note:** Thank you for reading and I hope that you enjoyed the chapter. Please let me know what you thought of it if at all possible.


	3. Chapter 3

**Disclaimer:** I own nothing involved in this story unless I invented it myself. This is written for fun, not for profit. All forms of feedback eagerly accepted. Concrit is loved the most, but everything is welcome.  
 **Author:** Higuchimon  
 **Fandom:** Yu-Gi-Oh Arc-V  
 **Series:** Angels, Demons,  & Deciding Factors|| **Story Title:** Demon's Poison  
 **Characters:** Shun, Yuuto, Ruri, Yuuri|| **Pairing:** N/A  
 **Word Count:** chapter: 2,192|| **story:** 6,640|| **Chapters:** 3/4  
 **Genre:** Friendship, Angst|| **Rated:** PG  
 **Challenge:** Diversity Writing Challenge, H8, multi-chap with exactly 4 chapters; Easter Egg Basket Advent 2016, day #8, mention at least 5 separate colors; Valentine's Day to White Day 2016 day #4, redo a challenge prompt (Dice Gods, Shun  & Yuuto friendship); Advent 2015, day #3, write about a friendship; Catch the Yuus & Bracelet Girls: Yuuto; Word Count Set Boot Camp, #31, 9,359 words  
 **Notes:** This takes place in the same world as **Angel's Rest** , and takes place after it. For reference, Ruri, Shun, and Yuuto are all angels, whilst Yuuri & Dennis are demons.  
 **Summary:** In escaping from Yuuri, Shun found himself injured by demon poison. Demon poison can do horrible things, even to an angel. Perhaps especially to an angel.

* * *

Shun couldn't move without everything hurting. His skin burned, his wings ached, his leg throbbed, and those were just the _outside_ pains. Inside, something even harsher and colder twisted around, scraping at him, clashing voices of _get out_ and _you don't belong here_ and _stay where you are_ and _you're safe you're home_ warred within him and he didn't know what to listen to or what to do.

He thought he moved; he couldn't see anything different to tell him that he had, just the same endless walls of violet flame that surrounded him.

Purple was good, wasn't it? Purple meant Yuuto. Purple meant home.

But there was still the driving need to get out, to flee as far from this place as he could, that he'd gone where he had no business going and the pain would last until he left there, and that wasn't right, that wasn't home, because Yuuto wouldn't do that to him, would he?

No, never. Not at all.

Then, a brush against his wings, feather-light and curious. He fought to open his eyes and see something more than the flames, and a face swam before him. A very familiar face, one that eased the pain within him.

"Yuu-to?"

For a moment he thought the other looked startled, then he smiled. He'd always loved Yuuto's smile, so gentle and compassionate.

But this one looked off, didn't it?

It was probably his fault. He was sick, wasn't he? Yes, and he wasn't seeing clearly, that was why he thought all those ridiculous things.

"It's me, K-Shun. I've come to take you home."

He was sick. That was why Yuuto's voice sounded so strange, so wickedly amused. That was it.

"Home?" Wasn't he home now? Or close to it? "I am...home?" He couldn't truly be certain anymore.

Yuuto slid closer to him, one arm going around him. "No. Our enemies have taken you, Shun, don't you reemember?"

Shun remembered a fight. Remembered being hurt. Remembered the flames igniting inside of him. That happened. He knew it.

"I… think so..." He started to stand up, trembling at how much that hurt even more. "I thought… I thought you were there..." Hadn't Ruri and Yuuto turned up there? He remembered that, somewhat.

"It's very complicated. I'll explain it once you're well again. But we have to leave now, before the imposters get back."

Imposters… that made sense in a way, Shun thought, stumbling outward, held up only by his own will and Yuuto's supportive arms, and he wasn't certain of how long the former would last. He'd been tricked. Now Yuuto was here to save him.

He'd never live this one down.

But he didn't care that much now, not so long as he could get out of here.

"What do you think you're doing? Stop! Let him go!" A voice he didn't quite recognize, though it held echoes of familiarity. Yuuto twisted his head around; Shun couldn't see his face like that. He didn't like that, he wanted to see Yuuto and know he was safe.

"I think I'm taking what is mine. And you'd best not try to interfere."

There was some kind of a rushing movement, Shun couldn't identify it beyond that, and then Yuuto moved quickly, one arm going up and down, and the sound of someone stumbling and falling.

"Yuuto? What's going on?" He _hated_ not knowing what was happening, not being able to parse all of this for himself. When he got hold of the one who'd done this to him…

Yuuto's hand brushed against the side of Shun's neck in a soothing motion. "Don't stress yourself. We'd better hurry before anyone else tries to stop us."

Shun couldn't move all that fast, but he gave it his very best. Yuuto was right. They needed to get away from here. Who knew what would happen if they didn't?

* * *

Yuuri wanted to laugh so very much. He'd never imagined it would be this easy. He needed to keep a good supply of this poison on hand in the future, just to see what else it could do. What if he dosed up Yuuto with it, or one of those other lookalikes? Would they become him, or something like him?

A project for the future, for certain.

For the present, though, he took off, Shun leaning against him, not able to fly as fast or as high as he normally could due to the extra weight. He hoped Dennis managed to keep the other two at bay, if he'd crossed paths with them at all. Plans didn't always work out the way he'd expected them to.

Granted so far today, his plans worked out better than he'd imagined they would, so he wasn't going to worry about it a great deal.

Keeping down low would help them hide as well. Angels didn't seem to grasp that someone could go _lower_ when they could fly.

 _I can't take him back to my place. They'll know where it is now._ That really didn't bother him very much; he didn't keep much there that he couldn't do without.

But he still needed a place to put Kurosaki until this poison ran its course and whatever changes either faded away or finished.

And that in and of itself gave him the idea of where to take his new prize.

It was off to his laboratory.

* * *

Yuuto couldn't escape the feeling of fear prickling down his neck as they entered what Dennis assured them was Yuuri's private home, where they could find a sample of the poison. They'd had luck so far, arriving when Yuuri wasn't there, but he didn't trust to luck to continue, not in this situation.

Ruri didn't seem to care at all, looking around in haste. "Where is it?"

"I don't know where he keeps it," Dennis admitted. "But you should probably hurry."

Yuuto wasn't going to argue about that. The faster they were out of here, the better. He started to carefully sort his way through everything, while Ruri rushed along, tossing things to the side and emptying anything that looked as if it could hold something else.

"Ruri, he's going to know we were here if you keep doing that," Yuuto pointed out. She tossed him a glance over one shoulder.

"What's he going to do, try to bring us up on charges of breaking and entering when he's _poisoned my brother_?"

He couldn't find an argument to that.

"You know, he has a safe where he keeps important things," Dennis said from where he lounged by the door. "At least he told me that he did." He waved one hand carelessly. "Not sure of where it is, but you might think about trying to find it."

The words hadn't passed Dennis's lips properly before Ruri started to pull down everything she hadn't pulled down already. Yuuto winced; he would've preferred a little more of a quiet operation, without any hint that they'd been there. Anything that could give them a few extra moments without Yuuri interfereing would be a good thing.

Ruri did not care. Ruri searched anywhere that could possibly hold a safe in it, a savage kind of snarl coming from her lips when she found it.

"What kind of a combination would he use?" Yuuto asked Dennis, who delivered an eloquent shrug.

"He doesn't tell me everything. And I've never needed to know."

Yuuto didn't entirely believe him on that. Something about all of this pricked at the back of his head, matching the fear that came with knowing Yuuri could return at any moment.

 _We were lucky that Yuuri wasn't here. And that Dennis could guide us here. And..._

Small points began to fall into place, as neatly as the pieces of a puzzle. Nerves solidified into ice as Yuuto rose up.

"Ruri, figure the safe out. We need to get out of here."

"What?" Ruri stared up at him. "You think Yuuri's coming back this soon?"

"No. It's not where he's going to be." That wasn't it at all. "It's where he is _right now_."

Ruri froze for a moment before she turned back to the safe and slammed one fist against it with all of her strength, shouting a word of opening as she did.

Yuuto didn't know if it was the spell or her blow that did it, but the door creaked open, revealing a small vial of something that glowed a viscious shade of poisonous purple. Ruri snached it up without hesitation.

"Come on, let's get out of here. Dennis, we'll get back to you on meeting Yuuya."

Yuuto moved too fast to notice if Dennis made any kind of a reply. Until they had this situation with Shun sorted out, he wasn't going to mention a word of what was going on to Yuugo or Yuuya.

* * *

Dennis watched as the two angels faded away into the distance, his features decidedly neutral. He glanced at the mess they'd left behind and shook his head. Yuuri could do his own cleaning; he'd probably prefer it.

 _He'll be busy with this for a while anyway._ He wanted to know just what happened with that other angel Yuuri mentioned, the one these two were so worried about. He didn't think Yuuri would bring him back here, so that left at least one other place.

Yuuri probably wouldn't be back this soon, but he slipped into the air himself, spiralling up and waiting until he knew for a fact that Yuuto and Ruri weren't going to be around to see him. Then he dropped down, searching until he found the right door, tucked away behind a slide of rock, where few could have found it even if they'd known it was there.

Silence awaited him, which said more than anything that Yuuri hadn't returned yet. Dennis made himself comfortable, sliding a tiny vial of something pale pink out of his pocket to admire in the starlight.

 _Angels are so stupid._

* * *

If it weren't for the fact demons had far greater strength than one might've thought for their size and build, whatever the size and build might've been, Yuuri couldn't have dragged Shun along the way that he did. The angel couldn't give nearly as much help now as he did in the beginning, stumbling and almost falling more than anything else, no longer able to fly, but careless twitches of his wings giving him the occasional boost so they were making some progress.

 _All right, this is enough._ Yuuri had no intentions of dragging himself all through the lands between the demon-haunted valley and the angel-infested mountains with Kurosaki half-flung over one shoulder. There wasn't any telling when the poison's effects would clear out of his system and he'd start actually putting up a fight.

Though every touch they shared gave Yuuri a far stronger sense of being with a fellow demon, which could mean so many different things. But he wasn't going to take any chances.

He stopped and unloaded Kurosaki against the trunk of a tree, brushing himself off afterward. Kurosaki still had some angel essence to him and that could get annoying.

But the next step remained the more important one. Yuuri closed his eyes and focused his mind, shaping an image from the very core of his soul.

"Starve Venom," he murmured, the words shaking the ground beneath him. For a moment nothing else seemed to have happened. Then the sound of great wings, far larger than angel or demon wings, cut through the night.

His dear dangerous dragon lowered itself between the trees to the clearing he'd chosen, bending a black-scaled head so he could rest one hand on it.

"I need a lift, Starve Venom. Would you take me to my laboratory?"

A low growl rumbled out from the great beast's chest and Yuuri patted again. "No, you can't eat the angel. He's not even a proper angel anymore. And I have plans for him."

Starve Venom did not speak in any language that anyone who wasn't Yuuri could understand, or possibly another dragon. Yuuri had never seen him encounter another dragon, so he didn't know. He also didn't care. For now he grabbed hold of Kurosaki by the back of his shirt and dragged him to the dragon.

"Yuuto?" Shun's eyes opened partway but didn't really appear to focus on anything. "Where are we?"

Yuuri decided now was as good a time as any to implement the next part of his plan. If the full change didn't happen, then it wouldn't matter. And if it did… well...why not?

"It's not Yuuto, remember? Yuuto is our enemy," Yuuri said, pulling himself closer to Kurosaki. "I'm Yuuri. Your friend." He set his lips closer to Kurosaki's ears, one hand moving down Shun's neck. "Your lover. Remember?"

The noise Shun made was far more confused than anything else as he tried to shake his head. Yuuri patted him gently.

"Don't worry about it right now, Shun." Using the angel's given name tasted strange, but he would get himself used to it, to continue his deception. "We're going home and you're going to feel _all better_ soon enough."

 **To Be Continued**

 **Note:** Thank you for reading and I hope that you enjoyed the chapter. Please let me know what you thought of it if at all possible.


	4. Chapter 4

**Disclaimer:** I own nothing involved in this story unless I invented it myself. This is written for fun, not for profit. All forms of feedback eagerly accepted. Concrit is loved the most, but everything is welcome.  
 **Author:** Higuchimon  
 **Fandom:** Yu-Gi-Oh Arc-V  
 **Series:** Angels, Demons,  & Deciding Factors|| **Story Title:** Demon's Poison  
 **Characters:** Shun, Yuuto, Ruri, Yuuri|| **Pairing:** N/A  
 **Word Count:** chapter: 2,719|| **story:** 9,359|| **Chapters:** 4/4  
 **Genre:** Friendship, Angst|| **Rated:** PG  
 **Challenge:** Diversity Writing Challenge, H8, multi-chap with exactly 4 chapters; Easter Egg Basket Advent 2016, day #8, mention at least 5 separate colors; Valentine's Day to White Day 2016 day #4, redo a challenge prompt (Dice Gods, Shun  & Yuuto friendship); Advent 2015, day #3, write about a friendship; Catch the Yuus & Bracelet Girls: Yuuto; Word Count Set Boot Camp, #31, 9,359 words  
 **Notes:** This takes place in the same world as **Angel's Rest** , and takes place after it. For reference, Ruri, Shun, and Yuuto are all angels, whilst Yuuri & Dennis are demons.  
 **Summary:** In escaping from Yuuri, Shun found himself injured by demon poison. Demon poison can do horrible things, even to an angel. Perhaps especially to an angel.

* * *

All the way home, Yuuto kept watching for any sign of either Yuuri or Shun. Shun should've stayed safe in his bed under the healer's care, but Yuuto wasn't prepared for _anything_ to go the way that it should tonight. Nothing else had.

Which meant he wasn't that surprised when he and Ruri landed back on the healer's balcony and found the healer furious, Shun gone, and Haya mewing inconsolably.

Ruri went to pick up the little cat after tossing the vial they'd found toward the healer. "That should be it. Where's my brother?"

The healer caught the vial and stepped right over to the table holding various implements that Yuuto didn't know the meaning of or use for other than remedying the poison.

"That demon took him. The one with the face like yours." A jerk of one wingtip toward Yuuto told them both what they'd feared happened. "I tried to stop him, but he moved too fast and was too strong."

"You did your best," Yuuto reassured them, going over to try to help soothe Haya. The little cat adored Shun and not having him around meant they'd have to put up with a very miserable cat until he returned.

A few tense moments passed, broken by the healer saying something that Yuuto both feared and expected.

"This isn't the poison. It's _a_ poison, but it's not the one that affected your brother."

Ruri's head snapped around, a flash of anger in her eyes. "What are you talking about?"

"Just what I said. I managed to get a very _small_ sample from his injury, not enough to make an antidote, but enough so I can tell if they match. They don't."

Cold hands of rage and fear pressed themselves all along Yuuto's spine. It made a horrid, evil kind of sense now, on why Dennis so easily agreed to lead them to Yuuri's place.

 _He distracted us. We believed because it was a poison that was locked up, it just had to be the one we were looking for. And while we were busy there, Yuuri came_ _ **here**_ _and took Shun away._

He could argue with himself later about it, he decided. Keeping Ruri from raging and finding Shun, and the actual poison, would have to take precedence.

"Has it been long enough since they left that they could be back in demon territory?"

The healer considered Yuuto's question. "I can't say for sure. Shun wasn't up to any flying by the time they left. Of course, if the demon had help of some kind, that could make a difference."

Yuuto did not want to hear that. But he had to acknowledge it was true, regardless of wanting or not. He didn't know what kind of help Yuuri could have, if he'd brought along an entire regiment of demons to help with his abduction or not, but it didn't matter, either.

Ruri either didn't bother with such practical thoughts or didn't care. She set Haya down on the bed and ran her fingers over the cat's head before picking up one of Shun's shed feathers – and it wasn't molting time, what was that doing here – and setting it in front of the cat.

"You play with that. We'll bring the real thing back in no time."

Haya sniffed at the feather, then turned away from it, curling up into the familiar loaf formation of a cat ready for a nap. Yuuto frowned before he caught Ruri's eyes.

"Have you ever known Haya to turn down playing with Shun's feathers?"

Ruri opened her mouth, then closed it again, slowly shaking her head.

The sooner they found Shun, the better. Something was going on that neither of them liked.

* * *

With Starve Venom to give a lift, it took almost no time at all to get to Yuuri's laboratory. He kept it far from the demon lands, mostly because he didn't want complaints about the smells or the screams. Not that many demons _would_ complain, but it had happened before.

Really, you slowly take apart _one demon_ just to find out what made them work, and all the rest acted like you'd done something wrong by _their_ standards.

Still, this was a far better place to keep his new plaything than anywhere else would be. Kurosaki would be very malleable for a while, as well as very much in pain, and Yuuri wanted no one complaining.

"So you got him."

Dennis, standing in the doorway. Of course. That meant the other angels likely were on their way back. Good thing he'd left when he had or they might've been annoying.

"Was there ever a doubt?" Yuuri asked, a smug tilt on his lips. "Now get over here and help me get him inside." If Dennis had to be there, he could at least be useful. "What happened on your end of things?"

"Just like we figured. They tore your place apart looking for the poison."

Yuuri snorted at that. As if he'd keep his personally developed poison with effects even he hadn't known about anywhere but on himself.

Though he somewhat suspected Dennis had stolen a sample of it. It was the kind of thing he would do. As long as the angels didn't get it _and_ Kurosaki Shun, he didn't care what Dennis had or what he did with it.

"Where do you want to put him?" Dennis asked, throwing a glance over his shoulder. There were two places; the experiment table where Yuuri had done many things involving blood, pain, and screaming – he kept it scrupulously clean, he wanted no infections around here – and the couch that he slept on when he didn't feel like going back home. The couch itself big enough for two – if they were friendly.

Yuuri intended to be very 'friendly' with Kurosaki Shun. For various meanings of 'friendly'.

"The couch. Move his wings carefully, I suspect he's in a great deal of pain there." Yuuri licked his lips in anticipation. "A great deal of pain everywhere, but there in particular.

Dennis gave them both a look, gaze moving from Kurosaki to Yuuri and back again.

"If I didn't know better, I'd think he's..."

"He's becoming one," Yuuri said, nodding. "Side effect of the poison: or perhaps a direct effect. I can't be sure right now. I'll have to investigate it later." He wanted to make certain that it couldn't be reversed, if that were the case. Why go to all the trouble of creating a demon out of an angel if it could be changed back?

He fixed Dennis with a stern look. "I'm going to make him one of us. He'll be even more loyal to me than you are, and he'll be convinced the angels deceived him and kept him from his true home." He turned his attention back to the half-slumbering, half-comatose creature on his couch and ran one possessive finger down his chest.

"He's going to be _mine_." Partly because of the whole disagreement in the forest earlier. Partly because the poison was already turning Shun into one of them and why turn down the chance to play with a new toy?

And partly because Yuuto, his hated face-twin, counted Shun as one of his and Yuuri would take that away from him and ruin it in every way that he could.

"I've already told him that he and I are lovers," Yuuri continued, a satisfied smirk pulling itself over his lips. "And I intend that to be true as well." He wondered if Shun had any real experience. Well, if he didn't yet, he would once Yuuri had time to attend to it.

Dennis leaned back, a smile of his own flashing by. "And just how do you plan on convincing him of all of that?"

"He's in no condition to know otherwise," Yuuri pointed out. "The poison hurts him more than I ever imagined. He'll listen to anything I say. He couldn't even tell me apart from Yuuto earlier." He stroked down Shun again. "And I'm going to take as much advantage of that as I can. All _you_ need to do is back me up when I need you to."

He watched Shun for another few minutes, not surprised that the other had lapsed into stillness and silence. Shun still twitched now and then, and when Yuuri bent his senses toward him, he could feel the demon essence growing stronger, burning out the angelic.

 _It needs help. Angels can't fall without a little help._

He didn't know if that were actually true or not, but the idea of 'helping' Shun become one of them appealed in every way he could imagine.

He leaned forward, brushing his fingers across Shun's shoulders and moving down to his wings, caressing gently. He wasn't usually gentle; he wasn't good at it. But while he thrilled to see others in pain, he refused to wreck his toy this soon. Suffering could come later, when Shun was in a condition to handle it.

"Shun," he murmured, continuing the gentle touches. It was his words that would contribute to Kurosaki's downfall tonight. "Shun, can you wake up?"

There was a low, pained groan. Kurosaki's eyes fluttered, and Yuuri continued the gentle caresses until he could see those confused, dazed eyes of pure gold. Not yet with a demon's slitted pupils, but soon. So very soon.

Yuuri didn't stop touching, his fingers moving up and down the darkening wings.

"You're still hurting, aren't you?" he murmured, gesturing to Dennis to bring a painkiller. He had plenty of those; it helped when his playthings could suffer longer. "I can fix that."

"Yuu-to?" Kurosaki murmured. Yuuri let out a deep sigh, as if disappointed.

"No, Shun. It's Yuuri. You don't remember me?" He pouted a fraction at that. "Has it been that long?"

Shun blinked, his eyes still vague and clouded. Yuuri took the painkilling potion Dennis brought over and carefully set it to Shun's lips.

"This will help you feel better," he promised, "You can trust me."

He thought Dennis laughed, but ignored it. Shun blinked again, then opened his mouth and drank the brew down. He leaned back on the couch, still more than a little confused and out of place. Yuuri counted on that.

"Yuuri," he murmured, staring at the demon. "You're Yuuri."

"That's right." Yuuri praised him with another stroke through his feathers. "The angels took you away a long time ago. They… did things to you." He shook his head slowly. "I didn't think we'd ever get you back."

He glanced up at Dennis. "Isn't that right?"

Dennis's reaction was off only by a hair. Not enough for someone as out of it as Shun was to notice. "That's right. We missed you!"

Shun tried to focus on Dennis. Yuuri kept up his touching, knowing the places where wings were the most sensitive to pain or pleasure.

"That's Dennis. We're all friends here. You've got nothing to be afraid of. I know you'll probably think we're your enemies and that you're an angel," Yuuri said, scrunching his nose as if such were the worst fate he could imagine. "But that's all due to what lies they fed you and the spells they used. I've been working on breaking them, to return you to your true form. It may take some time and it will keep on hurting until it's over with, but if you _want_ it to happen, it will happen a little faster."

Now he knew Dennis laughed and he shot him an annoyed look. Dennis calmed himself; he wasn't one of the best spies the demons had for nothing.

"I'll go check for any followers," he said, and was gone in a heartbeat. Yuuri wanted his absence more than his presence at the moment. Dennis being there could back up what he said, but if he couldn't keep his laughter under control, Shun might start to question matters.

Besides, Yuuri had every intention of debauching Shun as much as he could that night, and he didn't want an audience for that.

Not tonight, anyway.

Shun still didn't look as if he were completely there. That worked to Yuuri's advantage and he continued to caress, hands finding more places that he knew Shun would enjoy feeling gentle touches on.

"You and Dennis and I grew up together," Yuuri murmured, letting the soft words flow into Shun's pain and pleasure distracted mind, where they would take firm root. "The angels attacked over two hundred years ago and took many of us prisoner." That was an outright lie. "We didn't know if any of you survived. But a century ago, we saw you again." Truth, but that had been the first time he'd ever met Shun. "You were so different. Twisted into an angel's form."

He leaned forward to brush his lips across Shun's. "But still beautiful."

Something on the border of truth and lies. Shun was indeed beautiful, but the differences now came from him becoming a demon. Yuuri found him even more attractive like this.

He kept spinning his web, though, and knew that Shun took in every word, even as the pain eased and the pleasure began to increase. "You nearly killed Dennis then. But from then on, I've been working to find something that would help you become your true self again. And I found it. I just wish it didn't hurt you so much."

That had to be one of the worst – or best – lies that he'd ever told. And Shun accepted every word of it.

* * *

Shun tried to breathe even as the pain eased. He didn't know if it had to do with the medication he'd drunk or what, but he did know he didn't hurt as much as he had. That meant he could focus on what he was hearing.

He thought he remembered every moment of his life among the angels, moments that couldn't be fabricated. At least he thought they couldn't.

Yuuri's hands kept touching him, not just on his wings, but his shoulders and moving down to his chest. Shun realized belatedly that he had very little on and no idea of where any of his clothes were.

"What are you..." Shun wanted to ask about that, but the words cut off when Yuuri's lips nipped into some sensitive territory.

"I spoke to our healer about what happened to you some time ago," Yuuri murmured. "I was told that this could help you recover. I wouldn't otherwise; you're not in the best condition." He looked up at Shun, large violet eyes worried. "But if you don't want to..."

Shun couldn't remember ever having done anything of the sort before. That fell from his lips before he could stop himself, and Yuuri frowned.

"The angels must've kept that from you. The monsters." He started to sit up. "We're not that repressed. There's nothing wrong with sex, Shun. Nothing at all." He settled himself next to Shun and continued to stroke in various places. Shun closed his eyes and tried not to think too much. It hurt to think right now in the first place, no matter how good his body began to feel.

He wasn't sure if Yuuri told him the truth or not, but he began to lean toward the thought he was. If they were actual enemies, then why would Yuuri try to make him feel good, of all things? Why would he do anything except hurt him?

Yuuri's touches didn't slow down and with each one of them, Shun could feel the pain from all over retreating, replaced by a rising pleasure that he wanted more of. He couldn't seem to speak the words, though.

"Only when you want me to," Yuuri murmured, and still Shun couldn't bring himself to say it. Not out of fear, not out of distrust – though in fairness he thought ghostly echoes of those remained – but a host of other reasons.

Chief among them being simple exhaustion. He closed his eyes and let himself slip away into the restful void. He could sort through all of this when he woke up, when he didn't hurt anymore.

* * *

Yuuri let him sleep. He wanted it now, but the rest would do Shun more good in the long run.

He had time. No one could find them here.

 **The End**

 **Note:** Thank you for reading and I hope that you enjoyed the story. Please let me know what you thought of it if at all possible.

 **Notes:** Next story, Shun's seduction by Yuuri. Just that. Say about eight or nine thousand words of naughtiness. Give me time, though. I have other stories that want telling.


End file.
